Well… so are a lot of weapons. For example, some contain mercury fulminate or other sources of mercury that may slowly be released into the environment, if not properly cared for. Mercury is a health hazard.
The thing is, for a nation it’s often worth the risk, if having the weapon keeps your enemies at bay.
The risk should not be downplayed or hidden though. One should be aware that weapons are dangerous in more than one way; not just going off.
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Just saying: I am not surprised. Sorry if anyone is, but it’s only natural.